Perpetual calendar



FIG. 1 is a perspective view of the perpetual calendar, according to my new design;

FIG. 2 is a front elevational view;

FIG. 3 is a rear elevational view;

FIG. 4 is a top plan view;

FIG. 5 is a bottom plan view of the perpetual calendar;

FIG. 6 is a side elevation looking in from the left of FIG. 1; and,

FIG. 7 is a side elevation looking in from the right of FIG. 1. 

The ornamental design for a perpetual calendar, as shown and described. 